Sascha Retzki wrote:
[ ... ]
> If I set the hostname, It says the same, but about the new hostname. I
> "echo myhostname > /etc/mail/local-host-names", which did not resolv the
> problem. I read somewhere that sendmail first queries dns servers, so I
> switched that off, too. Somewhere. Sometime. Somehow. (files local dns
> ?)

Well, you aren't likely to obtain a useful mail configuration without using 
DNS [1], so you need to fix that before you can expect sendmail to work. 
www.sendmail.org has extensive documentation and a FAQ on setting up 
pop-before-smtp, as well as better systems involving STARTTLS using X.509 
certs or USER AUTH mechanisms (ie, username & password-based access).

After getting plain SMTP going, you then need to set up an access map (or 
database), and then you convince your POP software to add and remove entries 
in the access map in order to get pop-before-smtp.

-- 
-Chuck

[1]: Yes, yes, I know more than I want to about FEATURE(`nocanonify'), and if 
you know what you're doing, you can go that way if you insist, or use UUCP, 
but for the sake of generalization, MTAs really want working DNS.